This invention relates to a rekeying tool for a lock assembly, shown in FIG. 1, for example, having a lock body with a locking cylinder rotatably alignable therein. The locking cylinder includes a plurality of radially extending bores (typically five to six) alignable with mating bores in the lock body. Each bore in the lock body includes an upper pin and corresponding spring biasing the upper pin toward an axially aligned lower tumbler pin in the corresponding mating bore of the locking cylinder. Further describing the bores in the locking cylinder body, each is perpendicular to and aligned in a row along the cylinder's axis.
Locks of this type tend to wear, particularly on the contact surfaces of the pins. For example, the pins in the locking cylinder are constantly rubbed by the key to adjust the position of the pins so that the cylinder may be turned within the lock body. The rubbing causes wear and eventually lock failure. This problem is often corrected by replacing the tumbler pins within the rotatable cylinder. Still further, select tumbler pins are replaced with pins of different length when rekeying the lock.
A problem is presented when rekeying or maintaining a lock, in that, when the lock cylinder is removed from the lock body, the upper pins, which remain disposed within bores in the lock body, are not positively maintained in position, and, since the same are resiliently urged into the space formally occupied by the cylinder, the upper pins and springs become dislodged from the bores in which they were originally positioned; therefore, necessitating the repositioning of the same before the lock is reassembled.
Since the upper pins positioned in the lock body do not wear, as do the lower tumbler pins, upper pins are not typically replaced with new pins. Therefore, there is often no reason for their removal when replacing the lower tumbler pins. However, the springs may sometimes need maintained and replaced if the spring force is damaged or worn with use. Still further, the pins in both the lock body and lock cylinder are relatively small in size, and the same are not readily repositioned without considerable effort on the part of the locksmith. As a result, the process of inspecting, maintaining and/or rekeying a lock is intricate, requires careful skill, and often time consuming.
The use of various lock servicing tools is known and includes different lock servicing devices as those shown in U.S. Pat. No. 5,628,109 issued May 13, 1997 to Martin Newman; U.S. Pat. No. 4,680,860 issued Jul. 21, 1987 to John C. Detloff; U.S. Pat. No. 4,675,994 issued Jun. 30, 1987 to John C. Detloff; U.S. Pat. No. 4,305,314 issued Dec. 15, 1981 to Ernest I. Simpson; U.S. Pat. No. 3,816,899 issued Jun. 18, 1974 to George J. Kitts; and U.S. Pat. No. 3,664,007 issued May 23, 1972 to Ernest L. Schlage.
While these devices may accomplish their particular objective, the aforementioned patents do not disclose a single-unit, lock rekeying tool made and used to more effectively inspect, maintain and retool the pins within locking cylinders having a tail extension. Moreover, various lock assemblies have differently designed lock bodies and cylinders. Some lock cylinders have various tail extensions. Therefore, multiple tools and steps are required to prevent the tumbler pins and springs from being dislodged while removing these types of locking cylinders. When rekeying or servicing such locks, the tail extension must be removed or two tools are needed to slide the locking cylinder from the lock body: a hollow tool and a solid tool. The locksmith must work with both tools interchangeably to gain access to the small pins and springs of the lock assembly.
More specifically, the first tool (i.e., having a hollow cross-section) is used to encase the tail extension. Otherwise, on account of the changing configuration and outside diameter of the locking cylinder (particularly at the transition between the tail extension and actual cylinder housing) pins and springs could easily dislodge as the cylinder is being guided from the locking cylinder. To make repairs and/or rekey the lock, a second tool (i.e., having a solid cross-section) is slid behind the hollow tool. The second tool is needed to better manipulate, repair and/or replace the several paired spring and pin combinations in the mating bores of the lock body. Finally, to re-assemble the locking cylinder in the lock body, the task is reversed (i.e., changing from the second tool back to the first tool) to slide the locking cylinder back in place in the assembly.